Class: ClusterManager

cluster-man~ ClusterManager

new ClusterManager(opts)

Utility class for creating new server clusters.
Parameters:
Name Type Default Description
opts object | function Options for the cluster or a worker function to execute on worker processes.
opt.worker cluster-man~Callback Function to execute on the worker processes.
opt.master cluster-man~Callback Function to execute on the master process.
opt.numWorkers Number Number of workers to spawn. Defaults to the value in `process.env.CLUSTER_WORKERS` if present, and if not then the number of CPUs as reported by `os.cpus().length`.
opt.debugScope String Root scope for debug logging. Defaults to the value in `process.env.CLUSTER_DEBUG` if present, and if not then defaults to 'cluster-man'.
opt.killOnError Boolean true Whether or not to kill the master process on and unhandled error.
opt.beforeExit cluster-man~BeforeExit Callback to execute before the master process exits in response to an error.
Author:
  • Ryan Sandor Richards.
Source:
Throws:
Error If a opt.worker was not specified or was not a function.
Examples
var ClusterManager = require('cluster-man');
var server = require('./lib/server');

// Basic usage (if you only need to handle workers)
new ClusterManager(server.start).start();
var ClusterManager = require('cluster-man');
var server = require('./lib/server');

// Create a new cluster manager using options, for handling master process
// and worker processes with a specific number of workers.
var serverCluster = new ClusterManager({
  worker: server.start,
  master: masterStart,
  numWorkers: 4
});

function masterStart(clusterManager) {
  // Any additional things you'd like to do after the cluster
  // has started...
}

// Start the cluster
serverCluster.start();

Methods

_addLogger(name, label)

Adds a logger debug method to the manager.
Parameters:
Name Type Description
name string Name of the logger method.
label string Output label for debug.
Source:

_exitMaster(erropt)

Runs before exit callback and exits the master process.
Parameters:
Name Type Attributes Description
err Error <optional>
 Error that caused the master process to exit.
Source:

_startMaster()

Starts a cluster master. Specifically this will bind worker events to specific handlers on this manager instance, fork all worker process, setup a domain to catch unhandled errors on the master process and execute the master process callback (as specified in the constructor).
Source:

_startWorker()

Starts a cluster worker. Simply executes the provided worker callback.
Source:

createWorker() → {cluster~Worker}

Creates a new worker. Specifically it forks a new worker, sets a domain error handler for the worker, and returns it.
Source:
Returns:
Newly created worker.
Type
cluster~Worker

disconnect(worker)

Handles worker `disconnect` events. This indicates that the worker has disconnected from communication but is not nessessarily dead.
Parameters:
Name Type Description
worker cluster~Worker Worker that disconnected.
Source:

exit(worker, code, signal)

Handles worker `exit` events.
Parameters:
Name Type Description
worker cluster~Worker Worker that exited.
code Number Exit code for the worker process.
signal String Signal name that caused the process to be killed.
Source:

fork(Worker)

Handles worker `fork` events. This event is emitted when a worker is forked off the master cluster.
Parameters:
Name Type Description
Worker cluster~Worker that was forked.
Source:

listening(Worker, address)

Handles worker `listening` events. Indicates to the master that a particular worker is listening.
Parameters:
Name Type Description
Worker cluster~Worker that is now listening.
address Address on which the worker is listening.
Source:

masterError(err)

Called when master process domain encounters an unhandled error. By default this method will log the error stack, indicate that the error is fatal, and kill the process with a status code `1`.
Parameters:
Name Type Description
err Error Unhandled error on the master process.
Source:

online(worker)

Handles worker `online` events. This indicates to the cluster that a worker process has successfully spawned a process and is running.
Parameters:
Name Type Description
worker cluster~Worker Worker that came online.
Source:

start()

Starts either a cluster master or a worker depending on the process type at the time of invocation.
Source: